/*
* Cryptographic API.
*
* Function for checking keys for the DES and Tripple DES Encryption
* algorithms.
*
* Originally released as descore by Dana L. How <how@isl.stanford.edu>.
* Modified by Raimar Falke <rf13@inf.tu-dresden.de> for the Linux-Kernel.
* Derived from Cryptoapi and Nettle implementations, adapted for in-place
* scatterlist interface. Changed LGPL to GPL per section 3 of the LGPL.
*
* s390 Version:
* Copyright (C) 2003 IBM Deutschland GmbH, IBM Corporation
* Author(s): Thomas Spatzier (tspat@de.ibm.com)
*
* Derived from "crypto/des.c"
* Copyright (c) 1992 Dana L. How.
* Copyright (c) Raimar Falke <rf13@inf.tu-dresden.de>
* Copyright (c) Gisle Sflensminde <gisle@ii.uib.no>
* Copyright (C) 2001 Niels Mvller.
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/crypto.h>
#define ROR(d,c,o) ((d) = (d) >> (c) | (d) << (o))
static const u8 parity[] = {
8,1,0,8,0,8,8,0,0,8,8,0,8,0,2,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,3,
0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,
8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
8,0,0,8,0,8,8,0,0,8,8,0,8,0,0,8,0,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,
4,8,8,0,8,0,0,8,8,0,0,8,0,8,8,0,8,5,0,8,0,8,8,0,0,8,8,0,8,0,6,8,
};
/*
* RFC2451: Weak key checks SHOULD be performed.
*/
int
crypto_des_check_key(const u8 *key, unsigned int keylen, u32 *flags)
{
u32 n, w;
n = parity[key[0]]; n <<= 4;
n |= parity[key[1]]; n <<= 4;
n |= parity[key[2]]; n <<= 4;
n |= parity[key[3]]; n <<= 4;
n |= parity[key[4]]; n <<= 4;
n |= parity[key[5]]; n <<= 4;
n |= parity[key[6]]; n <<= 4;
n |= parity[key[7]];
w = 0x88888888L;
if ((*flags & CRYPTO_TFM_REQ_WEAK_KEY)
&& !((n - (w >> 3)) & w)) { /* 1 in 10^10 keys passes this test */
if (n < 0x41415151) {
if (n < 0x31312121) {
if (n < 0x14141515) {
/* 01 01 01 01 01 01 01 01 */
if (n == 0x11111111) goto weak;
/* 01 1F 01 1F 01 0E 01 0E */
if (n == 0x13131212) goto weak;
} else {
/* 01 E0 01 E0 01 F1 01 F1 */
if (n == 0x14141515) goto weak;
/* 01 FE 01 FE 01 FE 01 FE */
if (n == 0x16161616) goto weak;
}
} else {
if (n < 0x34342525) {
/* 1F 01 1F 01 0E 01 0E 01 */
if (n == 0x31312121) goto weak;
/* 1F 1F 1F 1F 0E 0E 0E 0E (?) */
if (n == 0x33332222) goto weak;
} else {
/* 1F E0 1F E0 0E F1 0E F1 */
if (n == 0x34342525) goto weak;
/* 1F FE 1F FE 0E FE 0E FE */
if (n == 0x36362626) goto weak;
}
}
} else {
if (n < 0x61616161) {
if (n < 0x44445555) {
/* E0 01 E0 01 F1 01 F1 01 */
if (n == 0x41415151) goto weak;
/* E0 1F E0 1F F1 0E F1 0E */
if (n == 0x43435252) goto weak;
} else {
/* E0 E0 E0 E0 F1 F1 F1 F1 (?) */
if (n == 0x44445555) goto weak;
/* E0 FE E0 FE F1 FE F1 FE */
if (n == 0x46465656) goto weak;
}
} else {
if (n < 0x64646565) {
/* FE 01 FE 01 FE 01 FE 01 */
if (n == 0x61616161) goto weak;
/* FE 1F FE 1F FE 0E FE 0E */
if (n == 0x63636262) goto weak;
} else {
/* FE E0 FE E0 FE F1 FE F1 */
if (n == 0x64646565) goto weak;
/* FE FE FE FE FE FE FE FE */
if (n == 0x66666666) goto weak;
}
}
}
}
return 0;
weak:
*flags |= CRYPTO_TFM_RES_WEAK_KEY;
return -EINVAL;
}
EXPORT_SYMBOL(crypto_des_check_key);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Key Check function for DES & DES3 Cipher Algorithms");
